More than 300 mourners, including Prime Minister Julia Gillard and her partner, Tim Mathieson, paid their last respects to Courtenay on Wednesday afternoon at an intimate and private funeral at St Mark's Church, Darling Point.

Courtenay, who had planned much of the service himself in his final months with a professional event planner hired to co-ordinate it, had decreed it be a ''private'' ceremony, with only invited guests permitted at the historic sandstone church.

Ranking as one of Australia's highest-selling authors - more than 20 million books in 18 languages - he was farewelled by mostly friends and family members.

Courtenay's second wife, Christine, was surrounded by well-wishers, including television personality Jennifer Byrne, former Greens leader Bob Brown, entertainer Kamahl, former advertising colleague Alex Hamill and publishing figures Robert Sessions and Julie Gibbs.

Scenes from two films based on his books Jessica and The Power of One were screened before the service.

During the 90-minute service, billed as ''A Celebration'' in the order-of-service booklet, printed on what appeared to be a glossy book sleeve from one of his novels, mourners heard emotional tributes from his widow, sons Adam and Brett, former Sydney Olympics chief Simon Balderstone, and Mr Hamill.

Mr Sessions, Penguin Australia publisher, read the eulogy, in which he described Courtenay as man with a ''generosity of spirit'' and a keen eye not just for writing books but selling them, too.

Courtenay announced in September he was battling stomach cancer and died on November 22 but not before telling Mr Sessions his demise presented a marketing opportunity for what would become his final book, Jack of Diamonds, published just weeks ago .

''When he told me [about his cancer], I was speechless - but he wasn't. 'This is a great marketing opportunity … with my help Penguin can promote this as Bryce Courtenay's final book - we should sell twice as many as usual'.''

Mr Sessions said Courtenay's most challenging book was the account of his youngest son Damon's death after contracting medically acquired HIV, inspiring the 1993 bestseller April Fool's Day.

''Bryce said it was the hardest thing he had ever done, and the book deeply affected everyone who read it,'' he said.

Courtenay's first wife, the late Benita Solomon, was also recognised before the congregation heard about Courtenay's philanthropy and his love of teaching other writers, with a video screened of Courtenay at his ''Last Class'' writing workshop at the National Library of Australia in September.

A keen gardener who has a cymbidium orchid named after him, Courtenay's passion for the plant world was expressed in a guard of honour by his former students who held aloft sunflowers as his coffin left the church.